It is estimated that there are now over 12 million users of smokeless tobacco (snuff or chewing tobacco) in the United States. Between 1970 and 1985, the prevalence of smokeless use in the 12-25 year age group of males has increased from 1% to 26%. The increase in consumption of smokeless tobacco is of particular concern due to the addicting nature and physical dependence properties of smokeless tobacco products. Negative health consequences are also associated with the use of smokeless tobacco. During the past several years, this research site has systematically examined the behavioral and physical dependence aspects of smokeless tobacco use. Nicotine gum and/or behavioral treatment approaches have also been examined and demonstrated to be effective. The purpose of this grant proposal is to examine other potentially effective methods in the treatment of smokeless tobacco users. Since relapse is a significant yet unexplored area, an examination of factors associated with relapse and methods which can successfully prevent relapse will also be undertaken. The present proposal involves 2 major studies with 2 phases conducted over 5 years. The first phase of the first study will examine the effects of primary and secondary reinforcement properties of smokeless tobacco on craving, withdrawal symptoms and treatment outcome. This study will involve a 2x2 design where subjects will be assigned randomly and in a semidouble blind fashion to one of four treatments: transdermal nicotine system (TNS; primary reinforcement) versus placebo; and mint snuff (non-nicotine product with secondary reinforcement properties) versus mint snuff. The second phase of the first study will involve careful examination of factors associated with relapse to smokeless tobacco use. Subjects who are abstinent at the end of the first phase of this study will be followed for 6 months and asked about their smokeless tobacco use status, lapse and relapse situations, and coping skills used to circumvent lapse or relapse. The first phase of the second study will compare the most effective treatment of the first study with that of the study undertaken in the previous grant (nicotine gum versus placebo by intensive versus minimal behavioral intervention). These treatment conditions are hypothesized to be TNS and mint snuff versus nicotine gum. The dependent measures will include treatment outcome and withdrawal symptoms. The second phase of this second study will use the results from the previous relapse study to develop a structured and more specific questionnaire assessing relapse. This study will examine the frequency of situations perceived as relapse crises versus base rates of their occurrence. Subjects will be followed over a course of 12 months. These studies will provide a greater understanding of features associated with dependence on smokeless tobacco, alternative and effective methods for smokeless tobacco cessation, and a greater understanding of the relapse process.